1. Field of the Invention
The present invention relates to an optical waveguide with a light emitting device and an optical touch panel using the same.
2. Description of the Related Art
Conventionally, optical waveguides with branched structure for generating a plurality of light beams from one light emitting device are known (For example, US 2006/0188198 A1). Such optical waveguides are preferably used for emitting light beams to a coordinate input region of an optical touch panel. However, a conventional optical waveguide with a light emitting device suffered from its wide width and its low intensity of light beams emitted.
FIG. 6 shows one example of a conventional optical waveguide 60 with a light emitting device. As shown in FIG. 6, in the conventional optical waveguide 60 with a light emitting device, a plurality of branch points 62 are provided on a straight line perpendicular to a light guiding direction 64 of a main path 63 to uniformly distribute light emitted from a light emitting device 61. The optical waveguide 60 with a light emitting device had a wide width W3 because there were spaces (cladding layers) 66 among branched paths 65. Further, the optical waveguide 60 with a light emitting device was poor in optical transmission efficiency and the intensity of light emitted was low.
Conventional optical waveguides with light emitting devices had a disadvantage of having a wide width and a low intensity of light beams to be emitted. It is an object of the present invention to provide an optical waveguide with a light emitting device having a high intensity of light beams to be emitted.